HIGH SCHOOL STUDENTS' ECOLOGICAL UNDERSTANDING OF MATTER TRANSFORMATIONS

The focus of is presenting data from a study of high school students' understanding of matter transformations in physical and chemical changes in coupled human and natural systems connected with environmental literacy - the capacity to participate in evidence-based discussions of the effects of human actions on environmental systems. In science education, understanding the complex relationship between coupled human and natural systems, coupled biogeochemical and physical systems, and technology is important as the global ecological footprint expands.

We developed a test called Physical & Chemical Change Test for middle and high school students and included answer keys. Qualifying the content of the analysis, we viewed environmental systems as matter transforming system when we did analytic induction which governs the overall process of extraction and construction of the core theme of the study using phenomenological interpretation method.

Three characteristic properties that students attribute to solids or liquids, but not always to gases were found: Mass of gases: Through the chemical and physical changes of matter by sublimation, boiling, rusting, and burning, gaseous substances are regarded as having less weight than the source material of liquids or solids. Chemical identity of gases: Gaseous substance used as either reactant or product in chemical changes or involved in physical changes is often considered as air or forms mixture with air and is often confused with familiar gases such as O2 or CO2. Conservation of mass and chemical identity: Students do not view matter as being conserved between systems. When wood burns, matter burns. When iodine sublimes some of the mass is lost. When a person loses body fat it disappears and some of it comes out of the body as solid or liquid. They also focus on the conditions or forms of energy such as heat or pressure and consider those conditions as a reactants or products of matter transformations between coupled environmental systems.

The patterns in students' responses and limits to their understanding involve four big ideas in general theme of environmental literacy: Model-based reasoning, tracing matter through systems, connecting accounts of molecular, cellular, organismal, and environmental processes, and quantitative reasoning with data and models.